It appears that a certain type of quinque is edible for ghouls, as seen when a rampaging Ken Kaneki devours Yukinori Shinohara's Arata without any ill side-effects afterward. If the same can be said about the non-armor types is unknown at the time being. Only CCG's Rank 2 ghoul investigators and up are permitted to use quinques. The ghoul investigators transport them in bags or suitcases in order to store kakuhou.